CO_2 Reforming of CH_4 over Ni/CeO_2-ZrO_2-Al_2O_3 Prepared by Hydrothermal Synthesis Method

摘要

The Ni/CeO_2-ZrO_2-Al_2O_3 catalyst with different Al_2O_3 and NiO contents were prepared by hydrothermal synthesis method. The catalytic performance for CO_2 reforming of CH_4 reaction, the interaction among components and the relation between Ni content and catalyst surface basicity were investigated. Results show that the interaction between NiO and Al_2O_3 is stronger than that between NiO and CeO_2-ZrO_2. The addition of Al_2O_3 can prevent the formation of large metallic Ni ensembles, increase the dispersion of Ni, and improve catalytic activity, but excess Al_2O_3 causes the catalyst to deactivate easily. The interaction between NiO and CeO_2 results in more facile reduction of surface CeO_2. The existence of a small amount of metallic Ni can increase the number of basic sites. As metallic Ni may preferentially reside on the strong basic sites, increasing Ni content can weaken the catalyst basicity.